This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Roughly one-third of kidney transplants performed in the United States use kidneys from living donors. High blood pressure in a potential donor is generally considered to be a contraindication to living kidney donation because there is concern, though never proven, that this may increase the risk of kidney disease and worsened high blood pressure in the donor. Ambulatory blood pressure monitoring (ABPM) measures blood pressure multiple times over 24 hours while a patient wears a small, portable monitor and performs his or her usual activities. ABPM has been shown to be better at measuring a person's true blood pressure. We propose comparing clinic blood pressure and ABPM to determine the frequency with which the diagnosis of high blood pressure or normal blood pressure is changed by the ABPM recordings. Identifying cases of "white coat hypertension"-blood pressure that is high in the doctor's office but otherwise normal-- can expand the potential living donor pool, while identifying true cases of high blood pressure that were missed by a single clinic reading can protect potential donors from proceeding with a potentially harmful surgery. Though there are several studies evaluating living kidney donors after donation, no study has followed donors from the time prior to transplant. The studies that look back in time provide limited information because a high percentage of former donors within any group are not included and because there is no way to compare individual characteristics before donation with how well patients do. We propose examining ABPM recordings and markers of kidney disease at 6 month intervals following transplant to monitor changes in these values. Further, we will determine if patterns of ABPM recordings affect these changes. In most people, nighttime blood pressure is 10-20 percent lower than daytime blood pressure. This phenomenon is called "dipping" and the absence of dipping is associated with worsened kidney disease in patients with high blood pressure and diabetes. We propose obtaining ABPM recordings in transplant recipients both before and after transplant to determine whether the dipping status of the living donor has any effect on the dipping status of the transplant recipient or on the severity of high blood pressure in the recipient after transplant.